Revert "Send input event IPCs directly from the UI thread"

ipc/ipc_sync_message_filter.h

Index: ipc/ipc_sync_message_filter.h
diff --git a/ipc/ipc_sync_message_filter.h b/ipc/ipc_sync_message_filter.h
index 4b97646f1d983967fe238cf3812d5b155ce39041..02639778d679de1af9121f1ef5044ae28b105169 100644
--- a/ipc/ipc_sync_message_filter.h
+++ b/ipc/ipc_sync_message_filter.h
@@ -5,7 +5,6 @@
 #ifndef IPC_IPC_SYNC_MESSAGE_FILTER_H_
 #define IPC_IPC_SYNC_MESSAGE_FILTER_H_
 
-#include <memory>
 #include <set>
 #include <vector>
 
@@ -42,10 +41,6 @@ class IPC_EXPORT SyncMessageFilter : public MessageFilter, public Sender {
   void OnChannelClosing() override;
   bool OnMessageReceived(const Message& message) override;
 
-  // Like Send but may send immediately (instead of posting to the IPC thread)
-  // if the underlying Channel implements a thread-safe Send.
-  bool SendNow(std::unique_ptr<Message> message);
-
  protected:
   SyncMessageFilter(base::WaitableEvent* shutdown_event,
                     bool is_channel_send_thread_safe);